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This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A332472 The real part of the sum of unitary divisors function (usigma) generalized for Gaussian integers.

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%I A332472 #10 Feb 14 2020 03:21:48
%S A332472 1,1,4,-3,4,4,8,1,10,-12,12,-12,6,8,16,17,6,10,20,-12,32,12,24,4,-24,
%T A332472 -30,28,-24,8,-48,32,1,48,-38,32,-30,8,20,24,68,10,32,44,-36,40,24,48,
%U A332472 68,50,-40,24,-18,10,28,48,8,80,-64,60,-48,12,32,80,-63,-120
%N A332472 The real part of the sum of unitary divisors function (usigma) generalized for Gaussian integers.
%C A332472 If n = u * Product_{i} p_i^e_i, where u is a unit (1, i, -1 or -i), and p_i is a Gaussian prime with Re(p_i) > 0, then usigma(n) = Product_{i} (p_i^e_i + 1).
%C A332472 a(n) = A103228(n) for odd squarefree numbers (A056911), i.e., numbers n such that A318608(n) != 0.
%H A332472 Amiram Eldar, <a href="/A332472/b332472.txt">Table of n, a(n) for n = 1..10000</a>
%e A332472 a(4) = -3 since 4 = -(1 + i)^4 in Gaussian integers (i is the imaginary unit), so usigma(4) = (1 + i)^4 + 1 = -3, and a(4) = Re(-3) = -3.
%t A332472 f[p_, e_] := If[Abs[p] == 1, 1, (p^e + 1)]; usigma[n_] := Times @@ f @@@ FactorInteger[n, GaussianIntegers -> True]; a[n_] := Re[usigma[n]]; Array[a, 100]
%Y A332472 Cf. A034448, A103228, A332473 (the imaginary part), A332474 (the norm).
%K A332472 sign
%O A332472 1,3
%A A332472 _Amiram Eldar_, Feb 13 2020